Flexible display device

ABSTRACT

A flexible display device includes a flexible display module including a flexible display panel; a first frame and a second frame supporting the flexible display module; and a fixing coupler and an aligning coupler coupling the flexible display module with the first frame and the second frame, and the fixing coupler includes: a first fixing coupler fixing at least a portion of the first frame and at least a portion of the flexible display module; and a second fixing coupler fixing at least a portion of the second frame and at least a portion of the flexible display module, and the aligning coupler includes: a first aligning coupler fixed to another portion of the flexible display module; and a second aligning coupler fixed to another portion of the first frame and detachably coupled to the first aligning coupler.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/411,750, filed on May 14, 2019, which is a divisional of U.S. patentapplication Ser. No. 15/786,416, filed on Oct. 17, 2017, now U.S. Pat.No. 10,331,173, which claims priority to and the benefit of KoreanPatent Application No. 10-2016-0135864, filed on Oct. 19, 2016 in theKorean Intellectual Property Office, the entire content of each of whichis incorporated by reference herein.

BACKGROUND 1. Field

Aspects of embodiments of the present invention relate to a flexibledisplay device.

2. Description of the Related Art

In recent times, information technology devices equipped with a flatpanel display having excellent characteristics such as slimness, lightweight, and low power consumption have been widely used, as theinformation society has advanced. Among these, the screens ofsmartphones, which are comfortable to watch broadcasts and videos andsuitable for games, are becoming larger because many users prefersmartphones having a wide screen.

However, an increase of the screen size of the smartphone leads todegradation of portability, so there is a limitation in enlarging thescreen of the smartphone. Accordingly, users who are not satisfied withthe current screen size of the smartphone often carry a tablet computerfor playing games, watching videos, reading, and so on. However,carrying both a smartphone and a tablet computer is disadvantageous forportability.

In order to improve such portability, there has been a demand fordeveloping an electronic device such as a foldable smartphone. With thedevelopment of flexible display technology, foldable electronic devicescan be currently developed. The present invention relates to aconfiguration of electronic devices applied with a flexible displaypanel, e.g., a smartphone including a foldable display unit.

It is to be understood that this background of the technology section isintended to provide useful background for understanding the technologydisclosed herein, and, as such, this technology background section mayinclude ideas, concepts or recognitions that were not part of what wasknown or appreciated by those skilled in the pertinent art prior to acorresponding effective filing date of subject matter disclosed herein.

SUMMARY

According to an aspect of one or more embodiments of the presentinvention, a flexible display device includes a flexible display panelwhich is fastened by a jig to be folded, and a folded portion of theflexible display panel is detachably fastened to a support frame.According to another aspect of one or more embodiments of the presentinvention, a flexible display device includes a foldable flexibledisplay panel, and the flexible display device is improved in terms offlexure that occurs at a folding central portion of the flexible displaydevice.

According to another aspect of one or more embodiment of the presentinvention, a flexible display device is capable of minimizing orreducing defects that may occur in a curved portion thereof due to theuse over a long period of time, the flexible display device including aflexible display module including a flexible display panel, a framesupporting the flexible display module and an aligning couplerdetachably coupling the frame and a curved portion of the flexibledisplay module.

According to one or more exemplary embodiments, a flexible displaydevice includes: a flexible display module including a flexible displaypanel; a first frame and a second frame supporting the flexible displaymodule; and a fixing coupler and an aligning coupler coupling theflexible display module with the first frame and the second frame. Thefixing coupler includes: a first fixing coupler fixing at least aportion of the first frame and at least a portion of the flexibledisplay module; and a second fixing coupler fixing at least a portion ofthe second frame and at least a portion of the flexible display module.The aligning coupler includes: a first aligning coupler fixed to anotherportion of the flexible display module; and a second aligning couplerfixed to another portion of the first frame and detachably coupled tothe first aligning coupler.

The aligning coupler may further include a third aligning coupler fixedto another portion of the second frame.

The second aligning coupler and the third aligning coupler may belocated adjacent to each other at a boundary portion between the firstframe and the second frame.

The first aligning coupler may include a panel magnetic layer fixed tothe flexible display module and having magnetic properties. The secondaligning coupler may include a first frame magnetic layer fixed on thefirst frame and having magnetic properties.

The panel magnetic layer may include a first panel magnetic elementhaving a first surface polarity, and the first frame magnetic layer mayinclude a first frame magnetic element having a second surface polaritydifferent from the first surface polarity.

The panel magnetic layer may further include a second panel magneticelement being adjacent to the first panel magnetic element and havingthe second surface polarity, and the first frame magnetic layer mayfurther include a second frame magnetic element being adjacent to thefirst frame magnetic element, having the first surface polarity andfacing the second panel magnetic element.

The first panel magnetic element and the second panel magnetic elementmay be arranged alternately in a direction perpendicular to a boundaryportion between the first frame and the second frame. The first framemagnetic element and the second frame magnetic element may be arrangedalternately in the direction perpendicular to the boundary portionbetween the first frame and the second frame.

The first panel magnetic element and the second panel magnetic elementmay be arranged alternately in a direction of the boundary portionbetween the first frame and the second frame. The first frame magneticelement and the second frame magnetic element may be arrangedalternately in the direction of the boundary portion between the firstframe and the second frame.

The fixing coupler may further include: a first fixing coupler fixinganother portion of the first frame and a portion of the flexible displaymodule; and a second fixing coupler fixing another portion of the secondframe and a portion of the flexible display module.

The flexible display device may further include a hinge portionpivotally coupling the first frame and the second frame.

According to one or more exemplary embodiments, a flexible displaydevice includes: a flexible display module including a flexible displaypanel; a first frame and a second frame supporting the flexible displaymodule; and a fixing coupler and an electrostatic coupler coupling theflexible display module with the first frame and the second frame. Thefixing coupler includes: a first fixing coupler fixing at least aportion of the first frame and at least a portion of the flexibledisplay module; and a second fixing coupler fixing at least a portion ofthe second frame and at least a portion of the flexible display module.The electrostatic coupler includes a first electrostatic couplerdetachably coupling at least a portion of the first frame and at least aportion of the flexible display module.

The first electrostatic coupler may include a static electricitygenerator fixed on the first frame.

The flexible display device may further include a static electricityplate fixed to the flexible display module.

The flexible display device may further include a curvature sensorsensing a curvature of the flexible display module.

An electrostatic force of the static electricity generator may vary inaccordance with a sensing value of the curvature sensor.

The curvature sensor may include at least one of a magnetic sensor, apressure sensor, a proximity sensor, and an optical detection sensor.

The flexible display device may further include a hinge portionpivotally coupling the first frame and the second frame.

The foregoing is illustrative only and is not intended to be in any waylimiting. In addition to the illustrative aspects, exemplaryembodiments, and features described above, further aspects, exemplaryembodiments, and features will become apparent by reference to thedrawings and the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention will become moreapparent by describing in further detail some exemplary embodimentsthereof with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view illustrating a flexible display device;

FIG. 2 is a cross-sectional view illustrating the flexible displaydevice of FIG. 1;

FIGS. 3A and 3B show results of a flexure test of a flexible displaypanel;

FIG. 4 is a cross-sectional view illustrating a flexible display module;

FIG. 5 is a plan view illustrating a flexible display device accordingto an exemplary embodiment;

FIG. 6 is a cross-sectional view illustrating the flexible displaydevice of FIG. 5;

FIG. 7 is a mimetic view illustrating a folding action of the flexibledisplay module according to an exemplary embodiment;

FIG. 8 is a mimetic view illustrating a folding region of FIG. 7;

FIG. 9 is a mimetic view illustrating aligning by an aligning coupler;

FIG. 10 is a mimetic view illustrating a state in which positions arealigned by the aligning coupler of FIG. 9;

FIG. 11 is a plan view illustrating a flexible display device accordingto another exemplary embodiment;

FIG. 12 is a cross-sectional view illustrating the flexible displaydevice of

FIG. 11;

FIG. 13 is a plan view illustrating a flexible display device accordingto another exemplary embodiment;

FIG. 14 is a cross-sectional view illustrating the flexible displaydevice of FIG. 13;

FIG. 15 is a plan view illustrating a flexible display device accordingto another exemplary embodiment;

FIG. 16 is a cross-sectional view illustrating the flexible displaydevice of FIG. 15;

FIG. 17 is a perspective view illustrating a curvature sensor accordingto an exemplary embodiment;

FIG. 18 is a plan view illustrating a rollable display device accordingto another exemplary embodiment; and

FIG. 19 is a cross-sectional view illustrating the rollable displaydevice of FIG. 18.

DETAILED DESCRIPTION

Some exemplary embodiments will now be described more fully herein withreference to the accompanying drawings. Although the invention may bemodified in various manners and may have a number of exemplaryembodiments, some exemplary embodiments are illustrated in theaccompanying drawings and will be mainly described in the specification.However, the scope of the invention is not limited to the exemplaryembodiments described and shown herein and should be construed asincluding all variations, equivalents, and substitutions included in thespirit and scope of the invention.

In the drawings, thicknesses of layers and areas may be illustrated inan enlarged manner for clarity and ease of description thereof. When alayer, area, or plate is referred to as being “on” another layer, area,or plate, it may be directly on the other layer, area, or plate, or oneor more intervening layers, areas, or plates may be presenttherebetween. Conversely, when a layer, area, or plate is referred to asbeing “directly on” another layer, area, or plate, intervening layers,areas, or plates may be absent therebetween. Further when a layer, area,or plate is referred to as being “below” another layer, area, or plate,it may be directly below the other layer, area, or plate, or one or moreintervening layers, areas, or plates may be present therebetween.Conversely, when a layer, area, or plate is referred to as being“directly below” another layer, area, or plate, intervening layers,areas, or plates may be absent therebetween.

The spatially relative terms “below,” “beneath,” “lower,” “above,”“upper,” and the like, may be used herein for ease of description todescribe the relations between one element or component and anotherelement or component as illustrated in the drawings. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation, in addition tothe orientations depicted in the drawings. For example, in the casewhere a device illustrated in the drawing is turned over, the devicepositioned “below” or “beneath” another device may be placed “above”another device. Accordingly, the illustrative term “below” may includeboth the lower and upper positions. The device may also be oriented inanother direction, and, thus, the spatially relative terms may beinterpreted differently depending on the orientations.

Throughout the specification, when an element is referred to as being“connected” to another element, the element may be “directly connected”to the other element or “electrically connected” to the other elementwith one or more intervening elements interposed therebetween. It willbe further understood that the terms “comprises,” “including,”“includes,” and/or “including,” when used in this specification, specifythe presence of stated features, integers, steps, operations, elementsand/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components and/or groups thereof.

It will be understood that, although the terms “first,” “second,”“third,” and the like may be used herein to describe various elements,these elements should not be limited by these terms. These terms areonly used to distinguish one element from another element. Thus, “afirst element” described below could be termed “a second element” or “athird element,” and “a second element” and “a third element” may betermed likewise without departing from the teachings herein.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e. the limitations of themeasurement system). For example, “about” may mean within one or morestandard deviations, or within ±30%, 20%, 10%, or 5% of the statedvalue.

Unless otherwise defined, all terms used herein (including technical andscientific terms) have the same meaning as commonly understood by thoseskilled in the art to which this invention pertains. It will be furtherunderstood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and arenot to be interpreted in an ideal or excessively formal sense unlessclearly defined in the present specification.

Some of the parts which are not associated with the description may notbe provided in order to specifically describe embodiments of the presentinvention, and like reference numerals refer to like elements throughoutthe specification.

FIG. 1 is a perspective view illustrating a flexible display device.

Referring to FIG. 1, a flexible display device 1 according to anexemplary embodiment may include a flexible display module 100, a firstframe 210, a second frame 220, and a hinge portion 300.

The flexible display module 100 may include a touch screen which enablesan electrostatic or pressure sensitive touch input so as to receive auser's instruction or input in a touch manner.

Such a flexible display module 100 may output data, such as images,moving pictures, characters, and the like on a screen when the flexibledisplay module 100 is unfolded at a flat angle (e.g., 180 degrees).Further, a central portion of the flexible display module 100 may becurved or folded with respect to the hinge portion 300 such that thefirst frame 210 and the second frame 220 face each other.

A central portion of the flexible display module 100 which is foldedcorresponding to the hinge portion 300 has an area which is not fixed bya mechanical frame such that a natural curved surface may be formedwithout being subjected to external pressure during folding actions.

FIG. 2 is a cross-sectional view illustrating the flexible displaydevice 1 of FIG. 1.

Referring to FIG. 2, the flexible display device 1 includes a flexibledisplay panel 110, a support module 150, a first frame 210, a secondframe 220, a hinge portion 300, a first fixing coupler 410, and a secondfixing coupler 420.

The flexible display panel 110 may be curved at a curvature (e.g., apredetermined curvature) according to external pressure. To this end,the flexible display panel 110 may use a plastic substrate rather than acommonly used glass substrate and may use a low-temperaturemanufacturing process rather than a conventional manufacturing processso as to prevent or substantially prevent damage to the substrate.

The flexible display panel 110 may be, for example, an organic lightemitting diode (“OLED”) display panel. The OLED display panel may have aconfiguration in which an organic light emitting layer (not illustrated)formed on a flexible substrate, and a protective layer (not illustrated)protecting the organic light emitting layer are disposed. The flexibledisplay panel 110 may include pixels therein and may further include adriver (not illustrated) for driving each pixel.

The flexible display module 100 may include the flexible display panel110 and the support module 150 attached to a back surface portion of theflexible display panel 110. The support module 150 supports the backsurface portion of the flexible display panel 110 such that a screen ofthe flexible display panel 110 may maintain a constant plane. Thestructure of the support module 150 will be described below in moredetail with reference to FIG. 4.

The first frame 210 and the second frame 220 may be coupled to theflexible display module 100 or the flexible display panel 110,respectively, through the first and second fixing couplers 410 and 420.The first frame 210 and the second frame 220 support the flexibledisplay module 100, and a driver (not illustrated) for driving theflexible display panel 110 may be disposed on the first and secondframes 210 and 220. Outermost portions of the first frame 210 and thesecond frame 220 and an outermost portion of the flexible display panel110 may be directly coupled to each other through the first and secondfixing couplers 410 and 420, respectively.

The first and second fixing couplers 410 and 420 which couple the firstframe 210 and the second frame 220 with the flexible display module 100may include a pressure sensitive adhesive (PSA). The pressure sensitiveadhesive is a type of adhesives which may adhere to an adherend surfaceand may be firmly fixed by pressure. The pressure sensitive adhesive isexcellent in viscosity and elasticity, such that the pressure applied tothe flexible display panel 110 may be dispersed to prevent orsubstantially prevent breakage.

The hinge portion 300 is connected to each of the first frame 210 andthe second frame 220 and pivotally connects the first frame 210 and thesecond frame 220 such that the flexible display module 100 may beunfolded into a flat surface or folded like a book. The central portionof the flexible display module 100 includes a non-adhesive area which isnot coupled to or fixed to any of the first frame 210, the second frame220, and the hinge portion 300 so as to unconstrainedly form a curvedsurface during folding and unfolding actions.

When the first frame 210 and the second frame 220 are fully open to aflat angle (e.g., 180 degrees) such that the flexible display module 100becomes flat, as illustrated in FIG. 2, a flexure may occur at a centralportion of the flexible display module 100. The flexure of the centralportion of the display module 100 may occur because a back surfaceportion of a central area of the flexible display module 100 is notfixed by the frame. Accordingly, as the area that is not fixed to thefirst and second frames 210 and 220 increases, the flexure may becomelarger.

FIG. 3A shows results of a flexure test of the flexible display panel.

A graph of FIG. 3A shows flexural deformation that occurred when asample A and a sample B were held in a folded state for 240 hours in ahigh-temperature and high-humidity environment. The samples A and B inFIG. 3A are flexible display panels 110 that include a non-adhesiveportion having a length of about 8 mm at a central portion. A centralpoint of the flexible display panel 110 is set as a reference point at 0mm and areas on the left and right sides of the central point, eachhaving a length of about 4 mm which is not attached to the frame, is setas a non-adhesive area.

The test results show that the flexural deformation of the flexibledisplay panel 110 occurred at a maximum of about 60 μm or more. Asdescribed above, the flexural deformation occurring at the centralportion of the flexible display panel 110 may degrade the screenvisibility of the central portion.

FIG. 3B shows results of a flexure test of a flexible display panel.

A graph of FIG. 3B shows test results in a case in which the samples Aand B were held under substantially the same test condition as in FIG.3A except that a length of the non-adhesive area at the central portionwas reduced to about 4 mm.

Referring to FIG. 3B, in the flexible display panel 110 that has acentral point set as a reference point at 0 mm and non-adhesive areas onthe left and right sides of the central point, each having a width ofabout 2 mm, flexure occurred at a maximum of about 20 μm or more.

The test results of FIGS. 3A and 3B show that, as the non-adhesive areaat the central portion of the panel is reduced from about 8 mm to about4 mm, the flexural deformation at the central portion of the panel isimproved by about 40 μm.

FIG. 4 is a cross-sectional view illustrating a flexible display module.

Referring to FIG. 4, the flexible display module 100 includes theflexible display panel 110 and the support module 150 on the backsurface of the flexible display panel 110. The support module 150, in anembodiment, may include a light absorbing layer 151, a first adhesivelayer 152, a shock buffer layer 153, a second adhesive layer 154, a heatconductive layer 155, and a conductive layer 156.

In an embodiment, the flexible display panel 110 may be an OLED displaypanel including a light emitting layer on a flexible substrate. Theflexible display panel 110 having a multilayer structure may include athin film transistor (“TFT”) on the substrate and an OLED (notillustrated) electrically connected to the TFT.

The light absorbing layer 151, in an embodiment, includes a black lightabsorbing material and is disposed on the back surface of the flexibledisplay panel 110. The light absorbing layer 151 absorbs a reflectedlight that has been incident to a light incidence surface of theflexible display panel 110 and reflected therefrom, thereby improvingthe image quality of the flexible display panel 110.

The shock buffer layer 153 absorbs a part of a welding force applied tothe flexible display panel 110 to prevent or substantially preventdamage to the flexible display panel 110 and the first and second frames210 and 220. The shock buffer layer 153 may absorb a part of a stressapplied in the area where the flexible display panel 110 is folded inaccordance with the deformation of the panel. In addition, the shockbuffer layer 153 may allow the flexible display panel 110 to be attachedto the first frame 210 and the second frame 220 without bubbling in amanufacturing process of attaching the flexible display panel 110 withthe first frame 210 and the second frame 220. In an embodiment, theshock buffer layer 153 may include a non-metallic elastic material, suchas rubber or polyurethane, for example.

The first adhesive layer 152 may attach the light absorbing layer 151 tothe shock buffer layer 153 such that they may be fixed to each other. Inan embodiment, the first adhesive layer 152 may include a pressuresensitive adhesive.

The heat conductive layer 155 may conduct a local heat generated in alight emission screen of the flexible display panel 110 in a lateraldirection for the heat to be discharged. The heat conductive layer 155may include a material having high thermal conductivity, such as any ofa metal thin film, a graphite, and a metal-graphene composition. In anembodiment, the heat conductive layer 155 may have a thickness in arange from about 0.1 μm to about 10 μm. If the thickness is less thanabout 0.1 μm, the heat conduction efficiency may be insufficient,whereas if the thickness exceeds about 10 μm, there is a problem thatthe manufacturing cost increases due to excessive thickness. In anembodiment, the graphite used for the heat conductive layer 155 isexcellent in lateral heat conductivity along an arrangement direction ofthe carbon particles such that the local heat generated in the flexibledisplay panel 110 may be conducted in the lateral direction, therebypreventing or substantially preventing the pixels of the display panelfrom being damaged. In addition, the high temperature heat generation ofcircuit elements (not illustrated) located on the back surface of theflexible display panel 110 may not be locally transmitted to theflexible display panel 110.

The second adhesive layer 154 may attach the shock buffer layer 153 andthe heat conductive layer 155 to each other.

In an embodiment, the conductive layer 156 includes a conductive thinfilm, such as copper (Cu). In an embodiment, the conductive layer 156 isgrounded to maintain the ground potential such that the electrostaticdischarge (ESD) flowing from the outside may be shielded.

FIG. 5 is a plan view illustrating a flexible display device accordingto an exemplary embodiment.

FIG. 6 is a cross-sectional view illustrating the flexible displaydevice of FIG. 5.

Referring to FIGS. 5 and 6, a flexible display device 10 includes aflexible display panel 110, a first frame 210, a second frame 220, ahinge portion 300, a support module 150, a fixing coupler 410, and analigning coupler 500.

The first frame 210 and the second frame 220 may be pivotally coupled toeach other using the hinge portion 300. The hinge portion 300 allows theflexible display panel 110 to be folded or unfolded while the firstframe 210 and the second frame 220 rotate about a rotation axis. In astate in which the flexible display panel 110 is folded, a centralportion of the flexible display panel 110 overlapping the hinge portion300 becomes a hinge area.

The flexible display panel 110 may be a flexible display panel such asan OLED display panel, for example. The flexible display panel 110 mayinclude pixels therein and may further include a driver (notillustrated) for driving each pixel.

The flexible display module 100 may include the flexible display panel110 and the support module 150 attached to a back surface of theflexible display panel 110 to support the flexible display panel 110 tomaintain a constant plane.

The first frame 210 and the second frame 220 may be coupled to theflexible display module 100 by the fixing coupler 410 and the aligningcoupler 500.

The fixing coupler 410 which rigidly couples and fixes the first frame210 and the second frame 220 with the flexible display module 100 islocated mainly at an outside of the flexible display module 100, and mayinclude an adhesive member or a mechanical coupling member that is notuncoupled by external force.

In an embodiment, the fixing coupler 410 may include a pressuresensitive adhesive (PSA). Examples of the pressure sensitive adhesivemay include a natural rubber adhesive, a styrene/butadiene latexadhesive, an ABA block copolymer type thermoplastic rubber (where A is athermoplastic polystyrene terminal block and B is an intermediate blockof a polyisoprene rubber, a polybutadiene rubber, a polyethylene rubberor a polybutylene rubber), a butyl rubber, polyisobutylene,polyacrylate, an acrylic polymer adhesive such as polyacrylate or avinyl acetate/acrylic ester copolymer, and a vinyl ether-based polymeradhesive such as polyvinyl methyl ether, polyvinyl ethyl ether orpolyvinyl isobutyl ether.

On the other hand, the aligning coupler 500 detachably couples the firstframe 210 and the second frame 220 with the flexible display module 100such that the connection may be released even by a weak force.

The aligning coupler 500 includes a first aligning coupler 510 fixed tothe flexible display module 100, a second aligning coupler 520 fixed tothe first frame 210 and facing the first aligning coupler 510 to bedetachably coupled thereto, and a third aligning coupler 530 fixed tothe second frame 220 and facing the first aligning coupler 510 to bedetachably coupled thereto.

The second aligning coupler 520 and the third aligning coupler 530 mayoppose each other to be adjacent to each other at a boundary portionbetween the first frame 210 and the second frame 220. In an embodiment,the first frame 210 and the second frame 220 rotate by the hinge portion300, and the second aligning coupler 520 and the third aligning coupler530 may become spaced apart from each other (see FIG. 7).

The first aligning coupler 510, the second aligning coupler 520, and thethird aligning coupler 530 may each include a plurality of magneticelements. For example, the first aligning coupler 510 and the secondaligning coupler 520, which face each other, may include magneticelements having different surface polarities on facing surfaces,respectively. In addition, the third aligning coupler 530 may include,on a surface thereof facing the first aligning coupler 510, a magneticelement having a surface polarity different from that of the firstaligning coupler 510. The first aligning coupler 510 and the secondaligning coupler 520 may be detachably coupled to each other by anattractive force formed between the magnetic elements facing each other.Similarly, the first aligning coupler 510 and the third aligning coupler530 may be detachably coupled to each other.

Referring to FIGS. 5 and 8, the first aligning coupler 510 fixed to theflexible display module 100 may include a plurality of first panelmagnetic elements 511 and a plurality of second panel magnetic elements512 that are arranged alternately in a matrix form along a lateraldirection and a longitudinal direction of the flexible display module100. The first panel magnetic element 511 and the second panel magneticelement 512 are thin magnetic elements and may have surface polaritiesof “N” pole and “S” pole. The surface polarity of the magnetic elementmeans the magnetization polarity formed on surfaces of the panelmagnetic elements 511 and 512 facing frame magnetic elements.

The second aligning coupler 520 fixed to the first frame 210 may includea plurality of first frame magnetic elements 521 and a plurality ofsecond frame magnetic elements 522 that are arranged alternately in amatrix form at the first frame 210. The first and second frame magneticelements 521 and 522 have different surface polarities from those ofrespective facing ones of the first and second panel magnetic elements511 and 512.

For example, when the first and second panel magnetic elements 511 and512 have different surface polarities from those of the first and secondframe magnetic elements 521 and 522, respectively, it means that whenthe surface polarity of the first panel magnetic element 511 is “N”pole, the surface polarity of the first frame magnetic element 521corresponding to the position of the first panel magnetic element 511has “S” pole. Accordingly, a magnetic attractive force may act betweenthe first panel magnetic element 511 and the first frame magneticelement 521 having different surface polarities.

The third aligning coupler 530 fixed to the second frame 220 includes aplurality of third frame magnetic elements 531 and a plurality of fourthframe magnetic elements 532 that are arranged alternately in a matrixform. The third and fourth frame magnetic elements 531 and 532 havedifferent surface polarities from those of respective facing ones of thefirst and second panel magnetic elements 511 and 512, respectively. Inaddition, the third frame magnetic element 531 and the fourth framemagnetic element 532 may have the same surface polarities as those ofthe first frame magnetic element 521 and the second frame magneticelement 522, respectively. For example, a magnetic attractive force mayact between the first panel magnetic element 511 and the third framemagnetic element 531 having different surface polarities.

Referring back to FIG. 6, in a state in which the flexible displaymodule 100 is flatly unfolded, the first aligning coupler 510 of theflexible display module 100 is coupled to each of the second aligningcoupler 520 and the third aligning coupler 530.

The second aligning coupler 520 and the third aligning coupler 530 arelocated at a boundary portion between the first frame 210 and the secondframe 220 and face the first aligning coupler 510 parallelly thereto.The aligning coupler 500 formed at a curved surface portion of theflexible display module 100 may fix the central portion of the flexibledisplay module 100 to the first and second frames 210 and 220 throughthe coupling of the first aligning coupler 510 with the second aligningcoupler 520 and the third aligning coupler 530 such that flexure may notsubstantially occur at the central portion of the flexible display panel100 in the state in which the flexible display module 100 is fullyunfolded.

FIG. 7 is a mimetic view illustrating a folding action of the flexibledisplay module according to an exemplary embodiment.

FIG. 8 is a mimetic view illustrating a folding region of FIG. 7.

Referring to FIGS. 7 and 8, when the flexible display module 100 isfolded, the flexible display module 100 is deformed, having a curvature(e.g., a predetermined curvature) in the folding central area. On theother hand, although the first frame 210 and the second frame 220 arerotated by the hinge portion 300 to change a coupling angle, the frameitself includes a rigid material such as a metal or plastic and thus maynot be deformed.

As illustrated in FIG. 7, when the first frame 210 is rotated by thehinge portion 300 and the flexible display module 100 has a curvature,the coupling of the first aligning coupler 510 and the second aligningcoupler 520 may be partially released in a part of the coupling area. Inaddition, the coupling of the first aligning coupler 510 and the thirdaligning coupler 530 may be partially released in a part of the couplingarea.

If a flexible display module were strongly coupled with first and secondframes 210 and 220 in the entire area, the flexible display module mayreceive a strong stress at the curved portion. However, according to anexemplary embodiment, since the coupling of the flexible display module100 with the first and second frames 210 and 220 is at least partiallyreleased at the time of curvature formation, a natural curved surfacemay be formed without being substantially subjected to stress.

FIG. 9 is a mimetic view illustrating aligning by the aligning coupler500.

FIG. 10 is a mimetic view illustrating a state in which positions arealigned by the aligning coupler 500.

FIG. 9 is a schematic view showing an action of the aligning coupler 500while the flexible display module 100 is unfolded from the folded state.

In an embodiment, the first panel magnetic element 511 and the secondpanel magnetic element 512 at the flexible display module 100 arealternately disposed, having different surface polarities. In addition,the third frame magnetic element 531 and the fourth frame magneticelement 532 at the second frame 220 are alternately disposed, havingdifferent surface polarities.

When the flexible display module 100 is restored to the flat state fromthe folded state, the first aligning coupler 510 and the third aligningcoupler 530, which have been spaced apart from each other, may be seatedin a designated position in the proximity of each other. In the case inwhich a position of the flexible display module 100 deviates from thedesignated position, an alignment position of the first panel magneticelement 511 of the first aligning coupler 510 and an alignment positionof the third frame magnetic element 531 of the third aligning coupler530 may not correspond to each other. In such an exemplary embodiment, amagnetic attractive force is generated between the first panel magneticelement 511 and the third frame magnetic element 531. In addition, amagnetic repulsive force is generated between the third frame magneticelement 531 and the second panel magnetic element 512 due to the samesurface polarity. Accordingly, in the case in which the flexible displaymodule 100 deviates from the designated position on the second frame220, the flexible display module 100 may be automatically aligned andseated at the designated position by the attractive forces and therepulsive forces formed between the first aligning coupler 510 and thethird aligning coupler 530.

FIG. 10 shows a state in which the first panel magnetic element 511 isaligned at a position corresponding to the third frame magnetic element531, and the flexible display module 100 is aligned at the designatedposition.

Although not illustrated, in an embodiment, the first panel magneticelement 511 and the second panel magnetic element 512 may be arranged ina line along a lateral direction or a longitudinal direction of theflexible display panel 110, forming a stripe shape. However, it shouldbe understood that the arrangement of the first and second panelmagnetic elements 511 and 512 and the third and fourth frame magneticelements 531 and 532 may be varied depending on the position of thecurved surface of the flexible display module 100 and the hingestructure.

FIG. 11 is a plan view illustrating a flexible display device accordingto another exemplary embodiment.

FIG. 12 is a cross-sectional view illustrating the flexible displaydevice of FIG. 11.

Referring to FIGS. 11 and 12, a flexible display module 100 is coupledto a first frame 210 and a second frame 220 at an outer edge portionthereof, using a fixing coupler 410. A support module 150 on a backsurface of a flexible display panel 110 is coupled to the first frame210 and the second frame 220 using an aligning coupler 500.

The aligning coupler 500 includes a first aligning coupler 510 fixed tothe flexible display module 100, a second aligning coupler 520 at thefirst frame 210, and a third aligning coupler 530 at the second frame220. The first aligning coupler 510 may include a first panel magneticelement 511 and a second panel magnetic element 512 which arealternately disposed in a matrix form in a lateral direction and alongitudinal direction of the flexible display panel 110.

The second aligning coupler 520 includes a frame magnetic element havinga surface polarity different from that of the corresponding panelmagnetic element at the first aligning coupler 510. In addition, thethird aligning coupler 530 includes a frame magnetic element having asurface polarity different from that of the corresponding panel magneticelement at the first aligning coupler 510.

In another embodiment, although not illustrated, the first panelmagnetic element 511 and the second panel magnetic element 512 may bearranged in a line along the lateral direction or the longitudinaldirection of the flexible display panel 110, forming a stripe shape.However, it should be understood that the arrangement of the panelmagnetic element may be varied depending on the disposition and designof a curved surface of the flexible display panel 110. In addition, apart of the frame magnetic element or a part of the panel magneticelement, on a plane, does not necessarily have to be a magnetic element.As long as the magnetic element is disposed in a facing area, themagnetic element in some areas may be replaced with a flat memberincluding a metal material.

FIG. 13 is a plan view illustrating a flexible display device accordingto another exemplary embodiment.

FIG. 14 is a cross-sectional view illustrating the flexible displaydevice of FIG. 13.

Referring to FIGS. 13 and 14, a portion of a flexible display module100, except a central curved portion of the flexible display module 100,is fixed to a first frame 210 and a second frame 220 using a fixingcoupler 410. The curved portion of the flexible display module 100 iscoupled to the first frame 210 and the second frame 220 using analigning coupler 500.

The aligning coupler 500 includes a first aligning coupler 510 attachedto the flexible display module 100, a second aligning coupler 520 at thefirst frame 210, and a third aligning coupler 530 at the second frame220.

FIG. 15 is a plan view illustrating a flexible display device 10′according to another exemplary embodiment.

FIG. 16 is a cross-sectional view illustrating the flexible displaydevice 10′ of FIG. 15.

Referring to FIGS. 15 and 16, a portion of a flexible display module100, except a central curved portion of the flexible display module 100,is fixed to a first frame 210 and a second frame 220 using a fixingcoupler 410. The curved portion of the flexible display module 100 iscoupled to the first frame 210 and the second frame 220 using anelectrostatic coupler 600.

The electrostatic coupler 600 may include a first static electricitygenerator 620 at the first frame 210, a second static electricitygenerator 630 at the second frame 220, and a static electricity plate610 attached to the flexible display module 100.

The first and second static electricity generators 620 and 630 aredevices for fixing a flat member using an electrostatic force. The firstand second static electricity generators 620 and 630 on the first andsecond frames 210 and 220 generate electric charges on a surface thereofand may fix the flexible display module 100 using an attractive forcegenerated between charged particles on the static electricity plate 610and charged particles on the first and second static electricitygenerators 620 and 630.

In an embodiment, the static electricity plate 610 may include amaterial having high dielectric constant such that dielectricpolarization may be easily generated by electrostatic force at the firstand second static electricity generators 620 and 630. Some examples ofcommonly used high dielectric constant materials may include silicon(Si), gallium arsenide (GaAs), Teflon, polystyrene, ceramics, and thelike.

The first static electricity generator 620 and the second staticelectricity generator 630 may be separately disposed on the first frame210 and the second frame 220, respectively. Alternatively, only onestatic electricity generator may be disposed at one of the first frame210 and the second frame 220.

The structure, the number, and the disposition of the static electricitygenerators may be variously modified according to the shapes of thefirst and second frames 210 and 220 and the structure of the hingeportion 300.

In an embodiment, since the first and second static electricitygenerators 620 and 630 are operated by electric power, the flexibledisplay device 10′ may include a curvature sensor 320 embedded in thehinge portion 300 such that electrostatic force of the first and secondstatic electricity generators 620 and 630 may be controlled or blocked.

FIG. 17 is a perspective view illustrating a curvature sensor accordingto an exemplary embodiment.

In an embodiment, the curvature sensor 320 may be embedded in the hingeportion 300 and may sense the folded state of the flexible displaymodule 100 by measuring a displacement of the hinge portion 300. Thecurvature sensor 320 may include any of various sensors, such as amagnetic sensor, a pressure sensor, a proximity sensor, and an opticaldetection sensor, for example.

FIG. 17 shows an embodiment of a magnetic sensor 330 applied to thecurvature sensor 320. In an embodiment, a magnetic sensor 330 includes awheel portion 331 connected to a rotation axis of the hinge portion 300and rotating in accordance with folding and unfolding of the flexibledisplay module 100, a projection 332 including a permanent magnetlocated outside the wheel portion 331, a second contact point 333 blocated to face the projection 332 and displacing in terms of positionaccording to a magnetic force of the projection 332, a sensor switch 333including a first contact point 333 a corresponding to the secondcontact point 333 b, and a housing 334 protecting the sensor switch 333and fixing a terminal drawn out from the sensor switch 333.

In an embodiment, the projection 332 is located on the wheel portion 331so as to face the sensor switch 333 in a state in which the flexibledisplay module 100 is fully unfolded. The first contact point 333 a andthe second contact point 333 b in the sensor switch 333 do not contacteach other in a state in which the flexible display module 100 isfolded. However, in the state in which the flexible display module 100is fully unfolded, the second contact point 333 b moves in accordancewith the magnetic force of the projection 332 and is electricallyconnected to the first contact point 333 a by contacting the firstcontact point 333 a.

The first and second static electricity generators 620 and 630 maydetect a short state of the sensor switch 333 to selectively fix theflexible display panel 110 on the first and second frames 210 and 220 bycontrolling static electricity. In addition, when the sensor switch 333is open, the operation of the first and second static electricitygenerators 620 and 630 may be interrupted to separate the flexibledisplay panel 110 from the first and second frames 210 and 220.

However, it should be understood that the magnetic sensor 330illustrated in FIG. 17 is merely provided as one example of thecurvature sensor 320, and, in other embodiments, the folding of theflexible display module 100 may be detected through any of variousswitch configurations.

FIG. 18 is a plan view illustrating a rollable display device 1100according to another exemplary embodiment.

FIG. 19 is a cross-sectional view illustrating the rollable displaydevice 1100 of FIG. 18.

Referring to FIGS. 18 and 19, the rollable display device 1100 includesa plurality of frames including frames 1210 and 1220, a plurality ofhinge portions 1300 connecting the plurality of frames, a support module1150 on the plurality of frames 1210 and 1220, a fixing coupler 1410coupling the support module 1150 and each of the plurality of frames,and an aligning coupler 1500. A rollable display panel 1110 is disposedat the support module 1150.

In an embodiment, the aligning coupler 1500 includes a first aligningcoupler 1510 coupled to the support module 1150, and a second aligningcoupler 1520 fixed to the frames 1210 and 1220, and the first aligningcoupler 1510 and the second aligning coupler 1520 include magneticelements facing each other and having different polarities,respectively.

In a state in which the rollable display device 1100 is fully spread,the first aligning coupler 1510 and the second aligning coupler 1520 maybe coupled to each other by a magnetic force. In addition, in a state inwhich the rollable display device 1100 is rolled, as illustrated in FIG.19, the first aligning coupler 1510 and the second aligning coupler 1520are spaced apart from each other such that the rollable display panel1110 may have a gentle curvature.

However, the rollable display device 1100 illustrated in FIGS. 18 and 19is merely provided as one example of a flexible display device appliedwith the aligning coupler according to an exemplary embodiment, and thepresent invention may be applied to various flexible display devicesother than the structure illustrated in an exemplary embodiment.

As set forth herein, according to one or more exemplary embodiments, theflexible display device may couple the lower portion of the substratewith the frame when the flexible display panel maintains the flat state,thereby improving the flexure phenomenon occurring at the foldingcentral portion.

While the present invention has been illustrated and described withreference to some exemplary embodiments thereof, it will be apparent tothose of ordinary skill in the art that various changes in form anddetail may be made thereto without departing from the spirit and scopeof the present invention.

What is claimed is:
 1. A flexible display device comprising: a flexibledisplay module comprising a flexible display panel; a first frame and asecond frame supporting the flexible display module; and a first couplerand a second coupler coupling the flexible display module with the firstframe and the second frame, wherein the first coupler comprises: a thirdcoupler fixing at least a portion of the first frame and at least aportion of the flexible display module; and a fourth coupler fixing atleast a portion of the second frame and at least a portion of theflexible display module, and the second coupler comprises: a fifthcoupler fixed to the flexible display module, a sixth coupler fixed onthe first frame and detachably coupled to the fifth coupler, and aseventh coupler fixed on the second frame and detachably coupled to thefifth coupler.
 2. The flexible display device as claimed in claim 1,wherein the second coupler comprises a panel magnetic layer fixed to theflexible display module and having magnetic properties, the sixthcoupler comprises a first frame magnetic layer fixed on the first frameand having magnetic properties, and the seventh coupler comprises asecond frame magnetic layer fixed on the second frame and havingmagnetic properties.
 3. The flexible display device as claimed in claim1, wherein the second coupler comprises a static electricity plate fixedto the flexible display module and having magnetic properties, the sixthcoupler comprises a first static electricity generator fixed on thefirst frame and detachably coupled to the static electricity plate, andthe seventh coupler comprises a second static electricity generatorfixed on the second frame and detachably coupled to the staticelectricity plate.
 4. The flexible display device as claimed in claim 1,further comprising a third frame supporting the flexible display module;a first hinge portion pivotally coupling the first frame and the secondframe; and a second hinge portion pivotally coupling the second frameand the third frame.
 5. The flexible display device as claimed in claim4, wherein the first coupler further comprises an eighth coupler fixingat least a portion of the third frame and at least a portion of theflexible display module.
 6. The flexible display device as claimed inclaim 5, wherein the second coupler further comprises: a ninth couplerfixed to the flexible display module; a tenth coupler fixed on thesecond frame and detachably coupled to the ninth coupler; and aneleventh coupler fixed on the third frame and detachably coupled to theninth coupler.